Table of Contents

Introduction & Top Questions
Physiography and geology
- Origin
- Submarine features
  - Oceanic ridges and fracture zones
  - Seamounts
  - Ocean basins
  - Continental rise, slope, and shelf
  - Trenches
  - Bottom deposits
- Surface features
  - Coasts
  - Islands
Climate
- Monsoon zone
- Trade-winds zone
- Subtropical and temperate zone
- Subantarctic and Antarctic zone
Hydrology
- Surface currents
- Deep (thermohaline) circulation
- Upwelling
- Surface temperatures
- Surface salinity
- Ice
- Tides
Economic aspects
- Mineral resources
- Biological resources
- Fisheries
- Trade and transportation
- Tourism
- Environmental impact of human activity
Study and exploration
- Early exploration
- Systematic investigations

Fast Facts

Indian Ocean summary
Related Content

How old is the Indian Ocean?

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The Indian Ocean is the smallest, geologically youngest, and physically most complex of the world’s three major oceans (the others being the Pacific and Atlantic). Although it first opened some 140 million years ago, almost all of the Indian Ocean basin is less than 80 million years old. By 36 million years ago the Indian Ocean had taken on its present configuration.

Related Q&A

What surrounds the Indian Ocean?